add workflow to fetch spdx licenses

Author: elrayle

.github/workflows/fetch-licenses.yaml

@@ -0,0 +1,28 @@
+name: Fetch Licenses
+
+on:
+    workflow_dispatch: # Allows manual triggering of the workflow
+    schedule:
+        - cron: '0 0 * * *' # Runs at midnight ET
+    push:
+        branches:
+            - elr/license-updates
+
+jobs:
+    fetch-licenses:
+        runs-on: ubuntu-latest
+
+        steps:
+            - name: Checkout Repository
+              uses: actions/checkout@v2
+
+            - name: Checkout SPDX Repository
+              uses: actions/checkout@v2
+              with:
+                  repository: spdx/license-list-data
+                  path: spdx
+
+            - name: Copy Licenses
+              run: |
+                  cp spdx/license-list-data/json/licenses.json cmd/licenses.json
+                  cp spdx/license-list-data/json/exceptions.json cmd/exceptions.json